Preliminary Study on the Distribution of Irrawaddy Dolphin, <i>Orcaella brevirostris</i>, in Banten Bay

Abstract

Irrawaddy dolphins ( Orcaella brevirostris ) are aquatic mammals with critically endangered status able to live in different water salinities habitats, like estuary, rivers and lakes. Banten Bay features estuarine area where rapid economic development, contributed from industry, ports, mining and fisheries, takes place, and thus the presence of Irrawaddy dolphins in the area faces various environmental threats. This research aimed to study the distribution of Irrawaddy dolphins in Banten Bay and explore environmental factors threatening its life. Dolphins observation was conducted from January 2013-February 2014, using direct visual effort by team of observer and indirect effort by local fishermen. Direct visual effort was performed on boat by three observers, with max imum vessel speed 15 km/hour and total length of transect was 404 Km. Indirect visual effort comprised of regular assessment by 32 local fishermen when they conducted capture fishing at two different areas (South and North of Banten Bay). Sightings data from direct and indirect visual observation compiled with respondents opinion were mapped using Arc View &reg GIS 3.3, resulting in distribu tion map of Irrawaddy dolphin in Banten Bay. Irrawaddy dolphin was most frequently observed in the northeast, south and central areas of the bay. Environmental threats alarming the lives of Irrawaddy dolphin in the Banten Bay may include noise pollution, boat accident and entanglement.